1. Field of the Invention
The present invention relates to securing of heat sinks to electronic packages; particularly to a heat sink clip capable of providing an adaptable compressing force applied to a heat sink for securely and readily retaining the heat sink to an electronic package, and a heat sink assembly employing such a heat sink clip.
2. Related Art
In order to reduce heat produced by high-speed computer Central Processing Units (CPUs) such as the Pentium IV produced by Intel(R) and the K8 produced by AMD(R), bigger and heavier heat sinks are becoming increasingly necessary. Strong resilient clips are often used to attach these heat sinks onto electronic packages.
An example of this kind of heat sink clip is disclosed in Taiwan patent publication No. 456586. The clip is usually integrally formed from a sheet of plastic or steel. The clip comprises a central pressing portion, and two resilient portions extending outwardly and upwardly from opposite sides of the pressing portion. Two locking portions depend from distal ends of the pressing portion, respectively. A locking hole is defined in each locking portion. In operation, the locking holes of the clip are lockably engaged with catches of a CPU socket. The pressing portion of the clip is deformably attached to a surface of a heat sink for securing the heat sink to a CPU mounted on the socket. Thus a resilient compressing force is applied to the heat sink by the clip. However, the resilient compressing force is invariable because it is provided only by the deformation of the clip. Therefore the clip lacks adaptability for use in various applications having different force requirements. Furthermore, the resilient compressing force tends to diminish over time due to fatigue.